Unloading mechanism for compressors



.932. COLLINS 1,843,917

UNLOADING MECHANISM FOR COMPRESSORS Filed April 20. 1929 2 Sheets-Sheet 1 INVENTQR. 'Zeszer Z. 0//// 7.5

J OKMM ATTORNEY.

Feb. 9, 1932. co Ns 1,843,917

UNLOADING MECHANISM FOR COMPRESSORS Filed April 20, 1929 2 Sheets-Sheet 2 0 EQ 1 at b *5 k\& r I O i:-

LJ Q W Q Q w h \QWMWW INVENTOR. [es/er 1. 0/0/75 BY uwammm ATTORNEY.

Patented Feb. 9, 1932 UNITED STATES LESTER L. COLLINS, or rnANKLm,rEN1vsYLvA1vrA, nssrenon 'ro CHICAGO. PNEU- PATENT orrica IVJZACII'IC TOQL COMPAIQ'Y, OF NEW YORK, N. Y., A-CORPO RATION OF NEW JERSEY UNLOADING MECHANISM non ooMrnEssoRs Application filed April 20,

This invention relates to air and gas, compressors and more particularly to automatically operated unloading mechanism there: fOI". I

One object of the invention is to provide improved apparatus for eifecting loading and unloading of. a compressor in well defined steps. a closer range of adjustment as well as'more definite and quicker action in response ,to changes in receiver pressure. Another ob ject is to provide compensating means 'capable of more accurate control. Another object is to provide a simplified arrangement for adjustingthe range of the apparatus. Other objects will be apparent from the detailed description which follows- In order to illustrate the invention, one concrete embodiment thereof is shown in the accompanying drawings, in which: Fig. 1 is a fragmentary and diagrammatic view of a variable volume compressor equipped with regulatingapparatus in accordance with the present invention Fig. 2 is an enlarged top plan viewof the regulator or governor shown in Fig. 1;

Fig. 3 is a side elevational view, partly in section, of the regulator or governor Fig. 4 is a diagrammatic view showing, in section,the power cylinder and the distributor cylinder withassociated portions of the compensating means; and I g V Fig. 5 is avbottom plan view of the fixed support for the regulator adjusting means.

In Fig. 1, a variable volume compressor is indicated at A arranged to be controlled by a fluid pressure governor or regulating apparatus 13.. The compressor-A has unloading devices 0, d, e, and f, arranged to be operated in the order given. Unloadingdevices c and d control clearance pockets-a and:a so that the compressor is adapted to be unloaded in five steps. When none of the unloading devices is actuated, the compressor operates. at full "load. On actuation ,ofunloadingdevice c, first stage unloading occurs and the right end of the compressor is half unloaded so that the compressor operates at load. On operation of, unloading: device cl, the oppositeor leftend of the compressor Another object is to establish shown) 1929. Serial N0. $56,695.

is half unloaded and the entire compressor operates at half load. On operation of unloading device e,;the right end is entirely unloaded and the compressor operates at A load. lWhen device f is actuated, the entire compressor is unloaded. The loading of the compressor in. stages is in the reverse order.

The'fluid pressure governor is shown in complete detail in Figs. 2, 3, and 4;. It comprises a support 6 uponwhich rests a casing 7 providing a chamber 8 in. which is disposed a diaphragm 9 providing a small chamber 10 Which is connected to the air receiver (not Pressure fluid admitted to chamber 10 ,acts through diaphragm 9 upon aglever arm 11 pivoted at 12 and provided'on its outer end with weights 13, Movement of arm 11 is transmitted through a yoke connection 1A to a floating lever 15 from which is suspended a fluid control or pilot valve 16 of the Mason regulator type. controlling passages 17and l8 leadingto opposite ends of a chamber in which reciprocates a power piston 19. The fluid controlledby valve 16 may be water under pressure from any suitable source. Piston 19 is rigidly connected by a link or cross-over 20' to a balancedpiston 21 movable inqacylinder 22 and serving as a dis.- tributing member for pressure fluid from the compressor receiver (not shown) which is admitted through i a conduit 23 opening into cylinder 22 within the space between the heads of balanced piston 21. Movement .of piston 21 to the left serves to admit pressure fluid'from the receiver in succession to chambers 24, 25, 26, and 27, from which lead pipes 24a, 25a," 26a, and 27a to the unloading devices 0, cl, 6, and f for effecting, respectively, first-stage, second stage, third stage, and fourth sta e or total unloading ofthe compressor. Tin opening 28 in cylinder 23 beyond the limit of movementwof piston 21, serves as a vent for chambers 24;,25, "26, and 27when pressure thereto.

Fluid pressure actuated compensating means are utillzedto restore pilot valve 16 to neutral position-after each movement of arm 11 thereby to control the movement of power piston 19 and distributing piston 21 in well defined steps so as to produce progressive stages of unloading and loading of the compressor. Such compensating means include a lever having a fulcrum pivot 29 with one arm 30 pivoted for slight relative movement at 31 to lever and the other arm 30a extending above chambers 2 l27 inclusive and provided adjacent its outer end with an adjustable weight 32. The fluid pressure admitted to chambers 24-27 inclusive, is utilized to move lever arm 30a positively to fixed positions which will restore pilot valve 16 to neutral position at each stage of unloading or loading. To this end, chambers 241427 inclusive, have slidable therein pistons 24?), 25b, 26b, and 27?), the stems of which are yieldingly maintained in contact with adjusting screws 33011 lever arm 30a by light coil springs 34L. The stems of pistons 2%- 276, inclusive, are of progressively greater length defining the projection of the pistons within the respective chambers, thereby to determine a fixed movement of lever arm 30a as pressure fluid is admitted successively to the chambers by control piston 21. The governor has an indicating device which comprises a pointer 35 (Figs. 2 and 3) which is secured to the connecting rod of power piston 19 and moves withthe latter along a dial strip 36 carrying indicia which show the op erating condition of the compressor.

The means for adjusting the operating range of the governor is an important feature of the present invention. It consists of apparatus for applying progressively greater resistance to the rising movement of arm 11. In the form shown it comprises a coil spring 37 attached at one end to a collar 38 slidably en aging arm 11 and secured in adjusted position by a locking screw 39. The opposite end of the spring is attached to a threaded rod 40 which extends through a slot 41a in a fixed support 41 (Figs. 2, 3, and 5) secured to base 6 as by screw bolts 42 and extending beneath arm 11. A nut 43, in threaded engagement with rod 40, abuts the lower face of support 4-1 and permits adjustment of the tension of spring 87. Coarse adjustment of the operating range of the regulator may be effected by moving the regulating assembly 38-40 longitudinally of arm 11 and support 41, and fine adjustment may be made by nut 43.

From the above it will be apparent that the present invention provides an improved compressor regulator or governor having fluid pressure means for restoring its pilot valve 16 to neutral position after each movement of lever arm 11, that such means operate quickly, positively, and accurately, and that oncethe stepped range of movement of pistons 246-276 is determined all subsequent adjustments in the operating range of the governor are made by the single spring tensioning device 384=0.

While the invention has been herein disclosed in what is now considered to be a pre ferred form, it is to be understood that the invenLion covers all changes, modifications, and adaptations within the scope of the appended claims.

I claim as my invention:

7 1. In a pump or compressor having a cylinder and a plurality of unloading devices arranged to unload the compressor in whole or in part, automatic regulating apparatus for controlling said unloading devices comprising a pilot valve controlled by receiver pressure, and fluid pressure actuated means for returning said pilot valve to neutral position after each movement. i I

2. In a pump or compressor having a cylinder and a plurality of unloading devices arranged to unload the compressor in whole or in part, automatic regulating apparatus for controlling said unloading devices comprising a pilot valve controlled by receiver pressure, fluid pressure actuated means for returning said pilot valve to neutral position after each movement, and means positively limiting the action of said first named means.

3. In a pump or compressor having a cylinder and a plurality of unloading devices arranged to unload the compressor in whole or in part, automatic regulating apparatus for controlling said unloading devices comprising a pilot valve controlled by receiver pressure, and fluid pressure actuated means for returning said pilot valve to neutral position after each movement including a plurality of plungers arranged to be actuated in succession.

4:. In a pump or compressor having a cylinder and a plurality of unloading devices arranged to unload the compressor in whole or in part, automatic regulating apparatus for controlling said unloading devices comprising a pilot valve controlled by receiver pressure, compensating means for returning said valve to neutral position after each movement, said last named means including a weighted lever, and fluid pressure actuated means for moving said lever against gravity in well defined steps.

5. In a variable capacity compressor having a cylinder with a plurality of unloading devices, automatic regulating apparatus for controlling said unloading devices comprising a weighted arm movable in response to receiver pressure, a pilot valve movable in response to movement of said arm, movable means controlled by said valve for distributing pressure fluid to said unloading devices, and fluid pressure actuated means controlled by'said first named means for restoring said pilot valve to neutral position after each movement of the same.

6. In a variable capacity compressor having a cylinder with a plurality of unloading -devices, automatic regulating apparatus for controlling said unloading devices comprising a pilot valve movable in response to receiver pressure, movable means controlled by said valve for distributing pressure fluid to said unloading devices, and means controlled by the pressure fluid released to said devices for restoring said valve to neutral position after each movement of the same.

7. In a variable capacity compressor having a cylinder with a plurality ofunloading devices, automatic regulating apparatus for controlling said unloading devices comprising a pilot valve movable in response to receiver pressure, a member controlled by said valve for distributing pressure fluid to said unloading devices, a lever associated With said valve, and means responsive to the pressure fluid released by said member for varying the position of said lever to move said valve to neutral position after each movement of the same in response to variations in receiver pressure.

8. In a variable capacity compressor having a cylinder with an unloading device, automatic regulating apparatus for controlling said unloading device and having a chamber with a connection to the latter, said apparatus comprising a pilot valve movable in response to receiver pressure, a member controlled by said valve and arranged to admit pressure fluid to said chamber, and means controlled by the pressure fluid released to said chamber for restoring said valve to neutral position after movement of the same including a Weighted lever connected to said valve, and a piston in said chamber arranged to move said lever a definite distance.

9. In a variable capacity compressor having a cylinder With an unloading device, automatic regulating apparatus for controlling said unloading device and having a chamber With a connection to the latter, said apparatus comprising a pilot valve movable in response to receiver pressure, a member controlled by said valve and arranged toadmit pressure fluid to said chamber and means controlled by the pressure fluid released to said chamber for restoring said valve to neutral position after movement of the same including a Weighted lever connected to said valve, a piston in said chamber arranged to move said lever a definite distance, and means for adjusting the extent of movement of said lever by said piston.

10. In a variable capacity compressor having a cylinder With an unloading device, automatic regulating apparatus for controlling said unloading device and having a chamber With a connection to the latter, said apparatus comprising a pilot valve movable in response to receiver pressure, a member controlled by said valve and arranged to admit pressure fluid to said chamber, and means controlled by the pressure fluid released to said chamber for restoring sald valve .to neutral position after movement of. the same including a Weighted leverconnectedto said valve, afpiston in said chamber having a stem projecting therefrom, resilient means acting upon said piston to maintain said stem in engagement With said lever, and means for'adjusting the extent ofmovement of said lever bysaid piston. i

11. In a variable capacity compressor having a cylinder With a plurality of unloading devices, automatic regulating apparatus for controlling said unloading devices and having a seriesv of chambers With outlets to said unloading devices, said apparatus comprising a pilot valve movable in response to receiver pressure, a member controlled by said valve and arranged to distribute pressure fluid to said chambers, and means controlled by the pressure fluid released to said chan1- bers for restoring said valve to neutral position after each movement of thesame including a Weighted lever connected tosaid valve, and pistons in said chambers, each-arranged to effect a definite movement of said lever.

12.v In a variable capacity compressor having cylinder with a plurality of unloading devices, automatic regulating apparatus for controlling said; unloading devices and hav- I ing a series of chambers with outlets to said unloading devices, said apparatus compris ing a pilot valve incnrable in response to receiver pressure, a .Inembercontrolled by said valve, and arranged to distributepressure fluid in succession to said chambers, and

means controlled by the pressure fluid re-,

leased to saidchambers'for .restoringsaid valve to neutral position after each movement of the same including a Weighted lever con nected to said valve,pistons in said chambers having extensions, springs yieldingly maintaining said piston extensions in contact with said lever, and means for adjusting-the eX tent of movement of said lever by each of said pistons;

' 13. A fluid pressure governor for a variable I volume compressor comprising a fluid cone trol valve, means for effecting movement of said valve in response to variations in receiver pressure, a movable member controlled by said valve, and fluid pressure actuated means for returning said valve to neutral position after each movement to cause said member to advance or' recede including a fluid pressure actuated member controlled by said movable member.

14:. A fluidjpressure governor for a variable 7 volume compressor comprising a Weighted arm movable in response to receiver pressure, a pilot valve movable in response to movement of said arm, a power piston controlledby said valve, said governor providing a plurality of chambers, a member actuated by said piston for distributing pressure fluid tosaid chame bers, compensating means actuated by the pressure fluid admitted to said chambers for restoring said valve to neutral position after each movement of said arm thereby to cause said piston to move in definite Well defined steps, and dial and pointer means for indicating the positions of said member relative to said chamber. 7

15. A fluid pressure governor for a variable volume compressor comprising a Weighted arm movable in response to receiver pressure, a pilot valve movable in response to movement of said arm, a power piston controlled by said valve, said governor providing a plurality of chambers, a member actuated by said piston for distributing pressure fluid to said chambers, compensating means for restoring said valve to neutral position after each movement of the same comprising a Weighted arm connected to said valve, and members in said chambers for actuation by the fluid pressure admitted thereto arranged to move or to permit movement of said last named arm successively in definite steps.

16. A fluid pressure governor for a variable volume compressor comprising a Weighted arm movable in response to receiver pressure, a pilot valve movable in response to movement of said arm, a power piston controlled by said valve, said governor providing a plurality of chambers, a member actuated by said piston for distributing pressure fluid to said chambers, compensating means actuated by the pressure fluid admitted to said chambers for restoring said valve to neutral position after each movement of said arm thereby to cause said piston to move in definite Well defined steps, and adjustable means for applying an increasing resistance to the movement of said arm.

17. A fluid pressure governor for a variable volume compressoig a fluid control valve, a movable member controlled by said valve, means for eiiecting movement of said valve in response to receiver pressure, fluid pressure actuated means for returning said valve to neutral position after each movement to cause said member to advance or recede including a fluid pressure actuated member controlled by said movable member, said receiver pressure responsive means comprising a Weighted arm movable against gravity by receiver pressure, a fixed support beneath said arm, and resilient means engaging both said arm and said support and adjustable longitudinally thereof.

Si 'ned by me at Franklin, in the county of Venango and State of Pennsylvania, this 16th day of April, 1929.

LESTER L. COLLINS. 

